1. Field of the Invention
The present invention relates to a casing for a condenser element having weakened wall sections.
2. Description of the Prior Art
Condenser elements in the shape of a can are known, some having a weak part in the form of two identical zones with a wall thickness of less than the thickness of the wall of the bottom part which surrounds these two zones. The zones are separated by a ridge, the thickness of which is more important than the thickness of the walls of the two zones. Such safety valves are known from U.S. Pat. No. 3,878,440, dated July 23, 1973, in which is disclosed a safety valve for an electrolytic capacitor applied to the bottom of a maltacross shaped covering. The disclosed configuration does not give sufficient rigidity to the base of the cover, enabling the cover to break under force of the coil exerted against the base and not because of the gases accumulated inside the envelope.
The problem is also addressed by a device disclosed in Brazilian Patent No. PI 8003911, dated June 19, 1980, in which is disclosed a shaped safety valve in the cover of a base. The safety valve has the shape of two half-moons separated by a central part where the half-moons are weakened. The disclosed configuration does not offer a safely operating safety valve when there is the production of gas within the envelope, since it does not always react and can cause an explosion of the cover or of the envelope.